BUYING BONNEVILLES

Ground zero for the modern classic. And regardless of the competition there is still much to recommend the pre-2015 Bonnie…

Iconic modern classic. Yours from just £3500.

REAR SUSPENSION

The Bonneville isn’t badly suspended as standard and provides more than adequate performance for urban bimbling. Riders heavier than 80kg should be sure to measure the sag and increase the spring preload accordingly to prevent the shocks bottoming out. Or for a little more plushness, Hagon 2810 shocks (£170) are a popular upgrade. Likewise, the basic damper rod front fork does a reasonable job of damping out rough roads but can easily be overwhelmed. Some owners choose to fit cartridge emulators.

CARBS

The early 790s and also the very first year of 865cc Bonnevilles run a pair of Keihin carbs, and the uprated T100 versions featured an electrically heated element to prevent carb icing in cold temperatures. These can be prone to gumming up if left sat for a long period of time, so require regular cleaning, or a dash of fuel stabiliser in the tank can help. The EFI bikes from 2007 onwards are easier to live with, and perform better.

SERVICING

The Bonneville is as low maintenance as motorcycles get. Strictly speaking it only requires an oil and filter change every 6000 miles, but it’s such a simple job that most owners do it themselves way before that interval, just because they feel like they should. A main dealer would probably charge around £150. Then there’s the valve adjustment which should happen at 12,000 miles, but because it’s rare to see a Bonnie with that sort of mileage, and also because being shim over bucket means they’re very rarely out of spec, it’s not something that gets done often. A 12k service will set you back around £370.

‘A Bonneville is about good-time motorcycling. Its charm comes from delivering simple pleasures’

BRAKES

The front brake caliper doesn’t stand up well to winter use because road salt and moisture cause pistons to stick. At the rear, the underslung caliper actuating the back brake can also seize if left standing for a long period of time. On the plus side, caliper rebuild kits are inexpensive and refreshing the simple sliding calipers is an easy job if you fancy an afternoon on the tools.

OIL PRESSURE SENSOR

An illuminated oil pressure warning light on the dash doesn’t necessarily mean there’s a broken oil pump or blocked oil way. Riding in the rain, or pressure washing the bike, can force water behind the oil pressure sensor’s protective rubber boot which causes the current running through it to ground and the warning light to come on. A coating of dielectric grease on the sensor solves the problem.

ENGINE

In a word – bulletproof. The parallel-twin oil/air-cooled motor with its 360-degree crank (the America and Speedmaster variants got a 270-degree for an uneven firing order and a bit more character) is about as unstressed as an engine can get. Early 790cc models make 62bhp and 44 lb.ft. torque, while 2007-onwards 865cc bikes make 67bhp and 55 lb.ft. torque, providing a small-but-noticeable boost to all-round rideability. Oil leaks are a thing of the past except for a few reported dribbles around valve cover gaskets that have perished slightly through age and heat.

LOOSE SPOKES

Some early 790cc models had wheels that were prone to breaking or losing spokes, particularly on the brake caliper side of the rear wheel. This was due to the original hub design which was prone to allowing spokes to get loose and then break. The spokes of pre-efi models should be checked for tightness every 3000 miles – a well-tuned ear will hear the difference in tone between a loose spoke and a tight one when it’s tapped with a spoke wrench. Later models had maintenance-free spoked wheels.